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A sustainable salt city in the desert

Published at: 30 September 2015

According to the United Nations more than 12 million hectares of land are lost to desertification and drought a year. 52% of the world’s land used for agriculture is affected – leading to problems for 1.5 billion people world wide. In the meantime the global population is ever increasing to an expected 9 billion in 2048 (UN World Population Prospects), meaning higher demand for food and the threat of an even quicker degradation of our soils due to exhaustion.

The Salt Project by 24 year-old TU Delft architecture graduate Eric Geboers, essentially proposes a building block made out of compressed salt. Geboers describes it as, "a biomimetic attempt to create architecture using seawater in the desert. By using locally available resources we can grow plants and create architecture without producing waste."

After a testing phase, the new building material proved to be as solid as other vernacular materials such as rammed earth or masonry. Like these materials, the salt bricks are strong in compression, which means they are more suited to rounded, arched or domed structures. "A fantastic property of the salt is its translucency when it’s cast or 3D printed in thin panels. When shining a light on it silhouettes behind the material become visible, leading to very interesting architectural possibilities." Aesthetically salt also presents some new options, Geboers says. "The colour of the material is obviously very white, a feature very handy in desert environments as it will reflect the sunlight as much as possible."

But the limitation of salt is obvious. "Of course the weak point of salt is the fact that it dissolves in water. This is currently being handled by applying a coating to the material. Currently research is being done to bio based coatings that damage the environment as little as possible. Other strategies for waterproofing the material could be building a transparent tent structure over it or covering it with things like reed or sand."

The project doesn’t just begin and end with the architecture; the production and maintenance of the salt involves creating a whole new ecosystem in dryland areas. The process would mean pumping up seawater through a solar-powered pipe system, to Seawater Greenhouses set up in a desert location. Here, the salt water is separated into salt and fresh water, which is used for produce.